1. Field of the Invention
The present invention relates to a manufacturing method of a side core type magnetic head slider used in manufacturing a magnetic head slider of a magnetic recording apparatus such as hard disk drives and floppy disk drives to be used as auxiliary storage devices for a computer.
2. Description of the Prior Art
In a magnetic head slider used in a magnetic recording apparatus at present, due to improvements in the recording density, since more information content must be recorded per unit volume and in order to improve the data transfer rate and to prevent damage of the head due to contact or collision with a medium, requests for lighter weights and further miniaturization have been intensified. Among these circumstances, a magnetic head used in the field of magnetic recording is broadly classified into two, groups, mainly a thin-film head and a ferrite head. In the ferrite head as shown in FIG. 13a, a slider comprises a housing 230 made of ceramics such as calcium titanate (CaTiO3), zirconia (ZrO2), non-magnetic ferrite or the like, and a ferrite core 130 being a magnetic material, and it is manufactured mainly by the machine work and high-temperature glass bonding.
After the slider 100 is completed, a coil for reading/writing signals via electromagnetic induction is wound to a leg 210 of a core part and is bonded to a predetermined position of a support spring (not shown) having flexibility. As above described, requests for miniaturization of magnetic head sliders are strong. Nanometer size sliders (also called 50% size sliders) shown in FIG. 13(a) are mainly used at present in hard disk drives, where the dimension in the thickness direction of the slider is 0.432 mm, and picometer size sliders (also called 30% size sliders) shown in FIG. 13(b) are expected to increase in usage, as they have a thickness dimension of 0.305 mm and are apt to become even thinner. With this tendency, dimension of the core part becomes small, and a thickness of the core in the nanometer size slider is 0.05xcx9c0.100 mm and dimension in a width direction is less than 0.8 mm. Further a magnetic wire of diameter 0.20 mmxcx9c0.025 mm is wound in several tens of turns by hand to a leg 210 of the small core part. In the prior art, such fine component parts are subjected to machining work and the processing work is performed by hand in each single part. During the work, reduction in the number of man-hours and improvement of the yield factor have been goals up to this point in time.
Numerals 190 and 200 denote the slope part, numeral 140 denotes a rail and numeral 220 denotes an apex in FIGS. 13(a), 13(b) and 14. In a head manufacturing process, when the head""s component parts become small, grasping of parts may fail, or parts may be lost during handling, or there may be a problem of breakage due to lack of strength. Also as shown in FIG. 14, since each of the component parts is treated as a single part of the core or slider, dispersion of the positioning accuracy of respective parts affects the machining accuracy and inhibits the quality stabilization.
In order to eliminate the above-mentioned disadvantages in the prior art, an object of the present invention is to provide a method of manufacturing a side core type magnetic head slider where the yield factor is good and the machining accuracy is high.
In order to attain the foregoing objects, the present invention provides the following manufacturing method. In a magnetic head slider including a ferrite core having a read/write gap and a housing of non-magnetic material with a rail on a surface opposite to a magnetic recording medium, core bond bars forming a chain of ferrite cores and a housing block are bonded to each other, the core bond bar and a housing plate are bonded to each other and machined into a plurality of slider plates and fine machining is applied thereto, and then the slider plates are separated into a plurality of magnetic head sliders. At the bonding portion between the housing plate and the core, the housing has a groove with a depth equal to a desired track width of the ferrite core, and a width equal to a width of the core bond bar. Also, the housing block is previously provided with a wiring groove at the side surface on which the core bond bar is mounted. After the core bond bar is bonded to the housing block, tapering work is applied at a prescribed angle to the side surface of the surface opposite to the medium, and during the grinding work from the rail surface the angle of the tapering work is adjusted so that when the track width is ground to a predetermined dimension, also a throat height becomes a predetermined dimension simultaneously.
At the beginning of the manufacturing process, component parts are not treated in each single body and the bonding and the machine work are applied to shape the core bond bar and the housing block in a size to tie easily handled. The component parts are separated into individual parts at a step near the end of the process thereby improving the machining accuracy, reducing the number of man-hours required, and improving the yield factor.